The present invention relates to marine craft having an impact protection arrangement. In particular, the present invention relates to marine craft capable of planing and which have an impact protection system.
By the term “marine craft capable of planing”, is meant marine craft which can obtain hydrodynamic lift by virtue of their speed across a body of water, rather than their lift being provided primarily by buoyancy.
Up to now, marine craft which are capable of planing have not been provided with any means of absorbing crash energy from high speed frontal impacts in a predictable and controlled manner. In order to plane, many marine leisure craft are capable of 30 knots (55 km/h) or more, hence impact closing speeds can be in excess of 60 knots (111 km/h). Such impacts may occur when the marine craft collides with another craft, with a jetty or with rocks, and can result in the sinking of the marine craft and serious injury to the helmsman and any passengers on board the craft. People on board marine craft often stand up, and those seated are generally not restrained with safety belts. Consequently, sudden deceleration of a marine craft due to a collision can cause people to be thrown over board.
Whilst frontal collisions are perhaps of most concern, collisions to the rear or a side of a marine craft may also result in injuries to occupants and severe damage to the craft, even though the impact speeds are generally lower. In respect of side impacts in particular, considerable deformation of the hull may be incurred through the intrusion of a bow of another craft. When hulls of small marine craft were made exclusively of wood, intrusion of the bow of another craft, even perpendicular to the gunwale, could result in considerable elastic deformation, but the wood would quickly spring back to its original shape without lasting damage. For all their maintenance advantages, more modern marine craft building materials, such as plastics or fibre reinforced plastics, are more liable to crack under impact. Thus even a relatively low speed impact to the side of a marine craft could result in the hull cracking and ultimately lead to the craft sinking.
It is known from U.S. Pat. No. 3,598,077, to provide a marine craft with an inflatable bow structure fitted externally of the main rigid bow and which is intended for cushioning the hull structure against wave impacts. An inflatable structure of this type would not be suitable for protecting the occupants of a marine craft from deceleration due to collisions; not least because of the strong likelihood of a sudden peak in deceleration as the inflatable structure burst on contact with another vessel or with a fixed obstruction. The structure requires large quantities of air to be supplied under pressure to maintain it in the inflated state. It is, therefore, principally intended for use in a craft having a hovercraft type inflatable outer skirt providing lift by virtue of air pressure supplied by fans, where the fans can also inflate the bow structure. Application of an inflatable bow structure to a conventional rigid hull craft capable of planing would require the use of fans specifically to inflate the bow. This would add significantly to the weight of the craft and would be a drain on the available power. Furthermore, the inflatable structure would increase the overall dimensions of the craft without improving its functionality in terms of additional storage space or vessel. components.